1

/*

     2

 *  matiec - a compiler for the programming languages defined in IEC 61131-3

     3

 *  Copyright (C) 2003-2011  Mario de Sousa (msousa@fe.up.pt)

     4

 *  Copyright (C) 2007-2011  Laurent Bessard and Edouard Tisserant

     5

 *

     6

 *  This program is free software: you can redistribute it and/or modify

     7

 *  it under the terms of the GNU General Public License as published by

     8

 *  the Free Software Foundation, either version 3 of the License, or

     9

 *  (at your option) any later version.

    10

 *

    11

 *  This program is distributed in the hope that it will be useful,

    12

 *  but WITHOUT ANY WARRANTY; without even the implied warranty of

    13

 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

    14

 *  GNU General Public License for more details.

    15

 *

    16

 *  You should have received a copy of the GNU General Public License

    17

 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.

    18

 *

    19

 *

    20

 * This code is made available on the understanding that it will not be

    21

 * used in safety-critical situations without a full and competent review.

    22

 */

    23

    24

/*

    25

 * An IEC 61131-3 compiler.

    26

 *

    27

 * Based on the

    28

 * FINAL DRAFT - IEC 61131-3, 2nd Ed. (2001-12-10)

    29

 *

    30

 */

    31

    32

    33

/*

    34

 * Definition of the Abstract Syntax data structure components

    35

 */

    36

    37

    38

/*

    39

 * ABSYNTAX.DEF

    40

 *

    41

 * This generates the parse tree structure used to bind the components

    42

 * identified by Bison in the correct syntax order. At the end of the

    43

 * Bison analysis the tree is walked in a sequential fashion generating

    44

 * the relavent code.

    45

 */

    46

    47

    48

    49

    50

    51

    52

/*****************************************************************/

    53

/*****************************************************************/

    54

/*****************************************************************/

    55

/*****************************************************************/

    56

/*                                                               */

    57

/*      safe<xxxxxx> Symbols are defined in:                     */

    58

/*      PLCopen - Technical Committee 5                          */

    59

/*      Safety Software Technical Specification,                 */

    60

/*      Part 1: Concepts and Function Blocks,                    */

    61

/*      Version 1.0 – Official Release - 2006-01-31              */

    62

/*                                                               */

    63

/*****************************************************************/

    64

/*****************************************************************/

    65

/*****************************************************************/

    66

/*****************************************************************/

    67

    68

    69

    70

    71

    72

    73

/*****************************************************************/

    74

/*****************************************************************/

    75

/*****************************************************************/

    76

/*****************************************************************/

    77

/*                                                               */

    78

/*             Symbols defined in:                               */

    79

/*      FINAL DRAFT - IEC 61131-3, 2nd Ed. (2001-12-10)          */

    80

/*                                                               */

    81

/*****************************************************************/

    82

/*****************************************************************/

    83

/*****************************************************************/

    84

/*****************************************************************/

    85

    86

/* Based on the                                    */

    87

/* FINAL DRAFT - IEC 61131-3, 2nd Ed. (2001-12-10) */

    88

    89

    90

/* EN/ENO */

    91

/* NOTE we store 'EN' and 'ENO' tokens in an identifier_c

    92

 *      as they may be used as variables, and it is much easier 

    93

 *      to handle them (fewer special cases) if we do it that way...

    94

 */

    95

/*

    96

SYM_REF0(en_param_c)

    97

SYM_REF0(eno_param_c)

    98

*/

    99

   100

/********************/

   101

/* 2.1.6 - Pragmas  */

   102

/********************/

   103

SYM_REF0(disable_code_generation_pragma_c)

   104

SYM_REF0(enable_code_generation_pragma_c)

   105

SYM_TOKEN(pragma_c)

   106

   107

   108

/***************************/

   109

/* B 0 - Programming Model */

   110

/***************************/

   111

SYM_LIST(library_c)

   112

   113

   114

/*************************/

   115

/* B.1 - Common elements */

   116

/*************************/

   117

/*******************************************/

   118

/* B 1.1 - Letters, digits and identifiers */

   119

/*******************************************/

   120

SYM_TOKEN(identifier_c)

   121

   122

   123

/*********************/

   124

/* B 1.2 - Constants */

   125

/*********************/

   126

   127

/******************************/

   128

/* B 1.2.1 - Numeric Literals */

   129

/******************************/

   130

SYM_TOKEN(real_c)

   131

SYM_TOKEN(integer_c)

   132

SYM_TOKEN(binary_integer_c)

   133

SYM_TOKEN(octal_integer_c)

   134

SYM_TOKEN(hex_integer_c)

   135

   136

/* Note:

   137

 * We do not have signed_integer_c and signed_real_c classes.

   138

 * These are stored in the parse tree as a integer_c or real_c

   139

 * preceded by a unary minus operator if they are inside an expression,

   140

 * or a neg_integer_c and neg_real_c when used outside an ST expression.

   141

 */

   142

/* Not required:

   143

SYM_TOKEN(signed_integer_c)

   144

SYM_TOKEN(signed_real_c)

   145

*/

   146

   147

/* NOTE: literal __values__ are stored directly in classes such as:

   148

 *          - real_c

   149

 *          - integer_c

   150

 *          - binary_integer_c

   151

 *          - etc...

   152

 *

   153

 *       However, for both the real_c and the integer_c, if they are preceded 

   154

 *       by a '-' negation sign, they are further encapsulated inside 

   155

 *       a neg_literal_c (i.e. the neg_literal_c will point to the 

   156

 *       real_c or integer_c with the value being negated.

   157

 *          neg_literal_c -> integer_literal_c

   158

 *                OR

   159

 *          neg_literal_c -> real_literal_c

   160

 *

   161

 *      In the semantic verification and code generation stages of the compiler,

   162

 *      the integer_c is treated as a basic (undefined) data type, since an integer

   163

 *      constant may be used as a BYTE, BOOLEAN, REAL, etc..., depending on the

   164

 *      context in which it is used.

   165

 *      However, an integer_c that is preceded by a '-' may not be used

   166

 *      as an ANY_BIT data type (BYTE, BOOLEAN, WORD, ...).

   167

 *      We must therefore be able to determine, holding a simple pointer

   168

 *      to an integer_c, if that integer_c value is preceded by a '-'.

   169

 *      However, since the neg_literal_c points to the integer_c, and not

   170

 *      vice-versa, we can't determine that.

   171

 *      There are 3 simple ways of working around this:

   172

 *        - change the order of the pointers: 

   173

 *              have the integer_c and real_c point to the neg_literal_c

   174

 *        - maintain the order of the pointers, and

   175

 *              add redundant info to the integer_c and real_c

   176

 *        - replace the neg_literal_c with two distinc classes

   177

 *              (neg_integer_c and neg_real_c), one for each

   178

 *              lietral type. This means that we can now treat

   179

 *              each of these classes as an unknown data type

   180

 *              just as we do with the integer_c and real_c.

   181

 *

   182

 *      The second option is simply ugly.

   183

 *      and the first has a serious drawback: when generating code it is

   184

 *      easier to encapsulate the real or integer values inside prefix

   185

 *      and postfix symbols (e.g. NEG(<value>) - with postfix ')' )

   186

 *      if we keep the pointer order as is.

   187

 *

   188

 *      For the above reasoning, we use the third option.

   189

 */  

   190

SYM_REF1(neg_real_c, exp)

   191

SYM_REF1(neg_integer_c, exp)

   192

   193

/* Not required:

   194

SYM_REF2(numeric_literal_c, type, value)

   195

*/

   196

SYM_REF2(integer_literal_c, type, value)

   197

SYM_REF2(real_literal_c, type, value)

   198

SYM_REF2(bit_string_literal_c, type, value)

   199

/* A typed or untyped boolean literal... */

   200

/* type may be NULL */

   201

SYM_REF2(boolean_literal_c, type, value)

   202

   203

/* helper class for boolean_literal_c */

   204

SYM_REF0(boolean_true_c)

   205

   206

/* helper class for boolean_literal_c */

   207

SYM_REF0(boolean_false_c)

   208

   209

   210

/*******************************/

   211

/* B.1.2.2   Character Strings */

   212

/*******************************/

   213

SYM_TOKEN(double_byte_character_string_c)

   214

SYM_TOKEN(single_byte_character_string_c)

   215

   216

   217

/***************************/

   218

/* B 1.2.3 - Time Literals */

   219

/***************************/

   220

   221

/************************/

   222

/* B 1.2.3.1 - Duration */

   223

/************************/

   224

SYM_REF0(neg_time_c)

   225

SYM_REF3(duration_c, type_name, neg, interval)

   226

SYM_TOKEN(fixed_point_c)

   227

SYM_REF2(days_c, days, hours)

   228

SYM_REF2(hours_c, hours, minutes)

   229

SYM_REF2(minutes_c, minutes, seconds)

   230

SYM_REF2(seconds_c, seconds, milliseconds)

   231

SYM_REF1(milliseconds_c, milliseconds)

   232

   233

   234

/************************************/

   235

/* B 1.2.3.2 - Time of day and Date */

   236

/************************************/

   237

SYM_REF2(time_of_day_c, type_name, daytime)

   238

SYM_REF3(daytime_c, day_hour, day_minute, day_second)

   239

SYM_REF2(date_c, type_name, date_literal)

   240

SYM_REF3(date_literal_c, year, month, day)

   241

SYM_REF3(date_and_time_c, type_name, date_literal, daytime)

   242

   243

   244

/**********************/

   245

/* B.1.3 - Data types */

   246

/**********************/

   247

/***********************************/

   248

/* B 1.3.1 - Elementary Data Types */

   249

/***********************************/

   250

SYM_REF0(time_type_name_c)

   251

SYM_REF0(bool_type_name_c)

   252

SYM_REF0(sint_type_name_c)

   253

SYM_REF0(int_type_name_c)

   254

SYM_REF0(dint_type_name_c)

   255

SYM_REF0(lint_type_name_c)

   256

SYM_REF0(usint_type_name_c)

   257

SYM_REF0(uint_type_name_c)

   258

SYM_REF0(udint_type_name_c)

   259

SYM_REF0(ulint_type_name_c)

   260

SYM_REF0(real_type_name_c)

   261

SYM_REF0(lreal_type_name_c)

   262

SYM_REF0(date_type_name_c)

   263

SYM_REF0(tod_type_name_c)

   264

SYM_REF0(dt_type_name_c)

   265

SYM_REF0(byte_type_name_c)

   266

SYM_REF0(word_type_name_c)

   267

SYM_REF0(dword_type_name_c)

   268

SYM_REF0(lword_type_name_c)

   269

SYM_REF0(string_type_name_c)

   270

SYM_REF0(wstring_type_name_c)

   271

   272

  /*****************************************************************/

   273

  /* Keywords defined in "Safety Software Technical Specification" */

   274

  /*****************************************************************/

   275

   276

SYM_REF0(safetime_type_name_c)

   277

SYM_REF0(safebool_type_name_c)

   278

SYM_REF0(safesint_type_name_c)

   279

SYM_REF0(safeint_type_name_c)

   280

SYM_REF0(safedint_type_name_c)

   281

SYM_REF0(safelint_type_name_c)

   282

SYM_REF0(safeusint_type_name_c)

   283

SYM_REF0(safeuint_type_name_c)

   284

SYM_REF0(safeudint_type_name_c)

   285

SYM_REF0(safeulint_type_name_c)

   286

SYM_REF0(safereal_type_name_c)

   287

SYM_REF0(safelreal_type_name_c)

   288

SYM_REF0(safedate_type_name_c)

   289

SYM_REF0(safetod_type_name_c)

   290

SYM_REF0(safedt_type_name_c)

   291

SYM_REF0(safebyte_type_name_c)

   292

SYM_REF0(safeword_type_name_c)

   293

SYM_REF0(safedword_type_name_c)

   294

SYM_REF0(safelword_type_name_c)

   295

SYM_REF0(safestring_type_name_c)

   296

SYM_REF0(safewstring_type_name_c)

   297

   298

   299

/********************************/

   300

/* B.1.3.2 - Generic data types */

   301

/********************************/

   302

   303

/********************************/

   304

/* B 1.3.3 - Derived data types */

   305

/********************************/

   306

/*  TYPE type_declaration_list END_TYPE */

   307

SYM_REF1(data_type_declaration_c, type_declaration_list)

   308

   309

/* helper symbol for data_type_declaration */

   310

SYM_LIST(type_declaration_list_c)

   311

   312

/*  simple_type_name ':' simple_spec_init */

   313

SYM_REF2(simple_type_declaration_c, simple_type_name, simple_spec_init)

   314

   315

   316

/* simple_specification ASSIGN constant */

   317

SYM_REF2(simple_spec_init_c, simple_specification, constant)

   318

   319

/*  subrange_type_name ':' subrange_spec_init */

   320

SYM_REF2(subrange_type_declaration_c, subrange_type_name, subrange_spec_init)

   321

   322

/* subrange_specification ASSIGN signed_integer */

   323

SYM_REF2(subrange_spec_init_c, subrange_specification, signed_integer)

   324

   325

/*  integer_type_name '(' subrange')' */

   326

SYM_REF2(subrange_specification_c, integer_type_name, subrange)

   327

   328

/*  signed_integer DOTDOT signed_integer */

   329

SYM_REF2(subrange_c, lower_limit, upper_limit)

   330

   331

/*  enumerated_type_name ':' enumerated_spec_init */

   332

SYM_REF2(enumerated_type_declaration_c, enumerated_type_name, enumerated_spec_init)

   333

   334

/* enumerated_specification ASSIGN enumerated_value */

   335

SYM_REF2(enumerated_spec_init_c, enumerated_specification, enumerated_value)

   336

   337

/* helper symbol for enumerated_specification->enumerated_spec_init */

   338

/* enumerated_value_list ',' enumerated_value */

   339

SYM_LIST(enumerated_value_list_c)

   340

   341

/* enumerated_type_name '#' identifier */

   342

SYM_REF2(enumerated_value_c, type, value)

   343

   344

/*  identifier ':' array_spec_init */

   345

SYM_REF2(array_type_declaration_c, identifier, array_spec_init)

   346

   347

/* array_specification [ASSIGN array_initialization} */

   348

/* array_initialization may be NULL ! */

   349

SYM_REF2(array_spec_init_c, array_specification, array_initialization)

   350

   351

/* ARRAY '[' array_subrange_list ']' OF non_generic_type_name */

   352

SYM_REF2(array_specification_c, array_subrange_list, non_generic_type_name)

   353

   354

/* helper symbol for array_specification */

   355

/* array_subrange_list ',' subrange */

   356

SYM_LIST(array_subrange_list_c)

   357

   358

/* array_initialization:  '[' array_initial_elements_list ']' */

   359

/* helper symbol for array_initialization */

   360

/* array_initial_elements_list ',' array_initial_elements */

   361

SYM_LIST(array_initial_elements_list_c)

   362

   363

/* integer '(' [array_initial_element] ')' */

   364

/* array_initial_element may be NULL ! */

   365

SYM_REF2(array_initial_elements_c, integer, array_initial_element)

   366

   367

/*  structure_type_name ':' structure_specification */

   368

SYM_REF2(structure_type_declaration_c, structure_type_name, structure_specification)

   369

   370

/* structure_type_name ASSIGN structure_initialization */

   371

/* structure_initialization may be NULL ! */

   372

SYM_REF2(initialized_structure_c, structure_type_name, structure_initialization)

   373

   374

/* helper symbol for structure_declaration */

   375

/* structure_declaration:  STRUCT structure_element_declaration_list END_STRUCT */

   376

/* structure_element_declaration_list structure_element_declaration ';' */

   377

SYM_LIST(structure_element_declaration_list_c)

   378

   379

/*  structure_element_name ':' *_spec_init */

   380

SYM_REF2(structure_element_declaration_c, structure_element_name, spec_init)

   381

   382

/* helper symbol for structure_initialization */

   383

/* structure_initialization: '(' structure_element_initialization_list ')' */

   384

/* structure_element_initialization_list ',' structure_element_initialization */

   385

SYM_LIST(structure_element_initialization_list_c)

   386

   387

/*  structure_element_name ASSIGN value */

   388

SYM_REF2(structure_element_initialization_c, structure_element_name, value)

   389

   390

/*  string_type_name ':' elementary_string_type_name string_type_declaration_size string_type_declaration_init */

   391

/*

   392

 * NOTE:

   393

 * (Summary: Contrary to what is expected, the

   394

 *           string_type_declaration_c is not used to store

   395

 *           simple string type declarations that do not include

   396

 *           size limits.

   397

 *           For e.g.:

   398

 *             str1_type: STRING := "hello!"

   399

 *           will be stored in a simple_type_declaration_c

   400

 *           instead of a string_type_declaration_c.

   401

 *           The following:

   402

 *             str2_type: STRING [64] := "hello!"

   403

 *           will be stored in a sring_type_declaration_c

   404

 *

   405

 *           Read on for why this is done...

   406

 * End Summary)

   407

 *

   408

 * According to the spec, the valid construct

   409

 * TYPE new_str_type : STRING := "hello!"; END_TYPE

   410

 * has two possible routes to type_declaration...

   411

 *

   412

 * Route 1:

   413

 * type_declaration: single_element_type_declaration

   414

 * single_element_type_declaration: simple_type_declaration

   415

 * simple_type_declaration: identifier ':' simple_spec_init

   416

 * simple_spec_init: simple_specification ASSIGN constant

   417

 * (shift:  identifier <- 'new_str_type')

   418

 * simple_specification: elementary_type_name

   419

 * elementary_type_name: STRING

   420

 * (shift: elementary_type_name <- STRING)

   421

 * (reduce: simple_specification <- elementary_type_name)

   422

 * (shift: constant <- "hello!")

   423

 * (reduce: simple_spec_init: simple_specification ASSIGN constant)

   424

 * (reduce: ...)

   425

 *

   426

 *

   427

 * Route 2:

   428

 * type_declaration: string_type_declaration

   429

 * string_type_declaration: identifier ':' elementary_string_type_name string_type_declaration_size string_type_declaration_init

   430

 * (shift:  identifier <- 'new_str_type')

   431

 * elementary_string_type_name: STRING

   432

 * (shift: elementary_string_type_name <- STRING)

   433

 * (shift: string_type_declaration_size <-  empty )

   434

 * string_type_declaration_init: ASSIGN character_string

   435

 * (shift: character_string <- "hello!")

   436

 * (reduce: string_type_declaration_init <- ASSIGN character_string)

   437

 * (reduce: string_type_declaration <- identifier ':' elementary_string_type_name string_type_declaration_size string_type_declaration_init )

   438

 * (reduce: type_declaration <- string_type_declaration)

   439

 *

   440

 *

   441

 * At first glance it seems that removing route 1 would make

   442

 * the most sense. Unfortunately the construct 'simple_spec_init'

   443

 * shows up multiple times in other rules, so changing this construct

   444

 * would also mean changing all the rules in which it appears.

   445

 * I (Mario) therefore chose to remove route 2 instead. This means

   446

 * that the above declaration gets stored in a

   447

 * simple_type_declaration_c, and not in a string_type_declaration_c

   448

 * as would be expected!

   449

 */

   450

/*  string_type_name ':' elementary_string_type_name string_type_declaration_size string_type_declaration_init */

   451

SYM_REF4(string_type_declaration_c,	string_type_name,

   452

					elementary_string_type_name,

   453

					string_type_declaration_size,

   454

					string_type_declaration_init) /* may be == NULL! */

   455

   456

   457

/*********************/

   458

/* B 1.4 - Variables */

   459

/*********************/

   460

SYM_REF1(symbolic_variable_c, var_name)

   461

   462

/********************************************/

   463

/* B.1.4.1   Directly Represented Variables */

   464

/********************************************/

   465

SYM_TOKEN(direct_variable_c)

   466

   467

/*************************************/

   468

/* B.1.4.2   Multi-element Variables */

   469

/*************************************/

   470

/*  subscripted_variable '[' subscript_list ']' */

   471

SYM_REF2(array_variable_c, subscripted_variable, subscript_list)

   472

   473

/* subscript_list ',' subscript */

   474

SYM_LIST(subscript_list_c)

   475

   476

/*  record_variable '.' field_selector */

   477

/*  WARNING: input and/or output variables of function blocks

   478

 *           may be accessed as fields of a structured variable!

   479

 *           Code handling a structured_variable_c must take

   480

 *           this into account!

   481

 */

   482

SYM_REF2(structured_variable_c, record_variable, field_selector)

   483

   484

/******************************************/

   485

/* B 1.4.3 - Declaration & Initialisation */

   486

/******************************************/

   487

SYM_REF0(constant_option_c)

   488

SYM_REF0(retain_option_c)

   489

SYM_REF0(non_retain_option_c)

   490

   491

/* option -> the RETAIN/NON_RETAIN/<NULL> directive... */

   492

/* NOTE: We need to implicitly define the EN and ENO function and FB parameters when the user

   493

 *       does not do it explicitly in the IEC 61131-3 source code. 

   494

 *       To be able to distinguish later on between implictly and explicitly defined

   495

 *       variables, we use the 'method' flag that allows us to remember

   496

 *       whether this declaration was in the original source code (method -> implicit_definition_c) 

   497

 *       or not (method -> explicit_definition_c).

   498

 */

   499

SYM_REF3(input_declarations_c, option, input_declaration_list, method)

   500

   501

/* helper symbol for input_declarations */

   502

SYM_LIST(input_declaration_list_c)

   503

   504

/* NOTE: The formal definition of the standard is erroneous, as it simply does not

   505

 *       consider the EN and ENO keywords!

   506

 *       The semantic description of the languages clearly states that these may be

   507

 *       used in several ways. One of them is to declare an EN input parameter, or

   508

 *       an ENO output parameter.

   509

 *       We have added the 'en_param_declaration_c' and 'eno_param_declaration_c' 

   510

 *       to cover for this.

   511

 *

   512

 *       We could have re-used the standard class used for all other input variables (with

   513

 *       an identifier set to 'EN' or 'ENO') however we may sometimes need to add this

   514

 *       declaration implicitly (if the user does not include it in the source